Effect of Some Plant Extracts on the Nematode Population and Yield Parameters of Waterleaf (Talinum triangulare L.) (Jacq.) Willd

Abstract

Studies were conducted on the nematicidal properties of Jatropha curcas, Cymbopogon citratus and Chromolaena odorata and Carbofuran 5G. Consequently, hot water extracts of the plants and the nematicide at 20, 35 and 50 % concentrations were applied to 5-week old stem cuttings of T. triangulare in 5 kg of sterilized soil and inoculated with 5,000 eggs and second stage juveniles of M. javanica. The control had no nematode, plant extracts and cabofuran, thereafter uninoculated-untreated (Uit) and another had nematode suspension, but no extracts and nematicide [inoculated-untreated (Ut)]. The experiment was a factorial in a completely randomized design, with four replications. Data on the number of leaves, seeds and flowers, nematode population in the soil and root of T. triangulare including root galling index were obtained and subjected to Analysis of Variance. Results show that number of leaves was significantly (P≤0.05) higher in Uit (25.75) and carbofuran at 20% concentration (21.0) than in the Ut (11.25). There were no significant differences in the number of flowers and seeds, although visual observations show that number of seeds was higher in Uit (13.5). Nematode populations in the root and soil were significantly lower in J. curcas at 50% concentration (30.0 and 9.0) respectively, compared to others at the same concentration except in carbofuran for nematode in the soil. Also, gall index was lowest in J. curcas extract at 50% concentration. Thus, J. curcas extract was more effective in managing root-knot nematode in waterleaf than cabofuran.

Key words: Carbofuran, Biopesticide, Talinum triangulare, Root-knot nematode.